By Jane Lewis
Two more studies reporting outcomes of the Testosterone Trials (T-Trials) – a set of seven placebo-controlled trials to determine the efficacy of testosterone gel use by US men aged 65 years or older with low testosterone – have been published in the Journal of the American Medical Association.
The JAMA studies were designed to examine the effect of testosterone treatment on memory and cognitive function (Resnick et al), and coronary artery plaque volume (Budoff et al), and follow a number of other T-Trials studies published last year.
Speaking to Medicine Today, Professor Rob McLachlan AM, Director of Andrology Australia, said the newly published studies add to the information that clinicians can provide their patients about the benefits and risks of testosterone treatment. However, he stressed that the men participating in the T-Trials were older with a range of comorbidities and ‘symptoms consistent with but not diagnostic of androgen deficiency,’ and therefore ought not be confused with ‘patients with testosterone deficiency due pathologies of the testis or pituitary.’
The first JAMA study, by Resnick et al, compared the effects of one year’s treatment with testosterone gel or placebo gel on the memory and cognitive function in 493 men with low testosterone levels and age-associated memory impairment. No significant differences were found between the two groups.
The second JAMA study, by Budoff et al, compared the effects of one year’s treatment with testosterone gel or placebo gel in 138 men with low testosterone levels on the progression of noncalcified coronary artery plaque volume (as measured by CT angiography). Compared with placebo, testosterone treatment was found to be associated with a significantly greater increase in noncalcified plaque volume.
Writing in an accompanying editorial, Professor David Handelsman from the ANZAC Research Institute, The University of Sydney and Concord Hospital, Sydney, concluded that ‘with the results of the studies by Resnick et al and by Budoff et al in this issue of JAMA, the hopes for testosterone-led rejuvenation for older men are dimmed and disappointed if not yet finally dashed.’
The findings of two additional T-Trials studies were also published recently, in JAMA Internal Medicine. These studies found that compared with placebo, the use of testosterone gel for one year improved bone mineral density and estimated bone strength (Snyder et al), and increased haemoglobin levels in men with unexplained anaemia, as well as those with anaemia from known causes (Roy et al).
Professor McLachlan noted that the fact that testosterone can have certain ‘drug effects’ on conditions such as anaemia does not mean it is appropriate for use as a therapy or clinical strategy to treat such conditions.
‘The guidelines we use in Australia discourage the prescription of testosterone in men other than those with low testosterone as a result of testicular or pituitary deficiencies,’ he said. ‘In older men who have low testosterone as a result of comorbidities such as obesity and diabetes, we need to focus on treating the comorbidities, not the testosterone levels.’
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Picture credit: © Sidney Moulds/SPL. Polarised light micrograph of crystals of testosterone.